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Your search keyword '"Theocharis, Andreas D."' showing total 2 results
Start Over Author "Theocharis, Andreas D." Topic magnetic hysteresis
2 results on '"Theocharis, Andreas D."'

1. Eddy-currents modelling in transformers magnetic cores using ohmic resistances.

Author

Theocharis, Andreas D., Olivares-Galvan, Juan Carlos, and Zacharias, Thomas

Abstract

The inclusion of eddy-currents effects in transformers cores is a very hot subject on transformers modeling. The dominated modeling approach is based on the usage of equivalent ohmic resistances placed in the equivalent electrical circuit which represents the electrical part of the transformer. In this paper, a comparison study, between the main different models using ohmic resistances for the eddy-currents in transformers magnetic cores, is conducted. Specifically, the selection of the suitable ohmic resistance, according to the study that is going to be conducted using an appropriate transformer model, is clarified; a topic that has not sufficiently been investigated and presented in the literature. The methods for determination of the ohmic resistances, in the simple case of a single-phase core-type transformer, are presented. Corresponding numerical results are given, which are compared to measured values if possible. [ABSTRACT FROM PUBLISHER]

Published
2012
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2. Three-Phase Transformer Model Including Magnetic Hysteresis and Eddy Currents Effects.

Author

Theocharis, Andreas D., Milias-Argitis, John, and Zacharias, Thomas

Subjects
*ELECTRIC transformers, *ELECTRIC resistors, *EDDY currents (Electric), *HYSTERESIS loop, *MAGNETIC cores, *MAGNETIC circuits, *MATHEMATICAL models, *ELECTRIC currents
Abstract

In this paper, a three-phase transformer model is developed to be suitable for slow transient and power-quality studies. The proposed model takes into account the eddy currents, the magnetic core topology, and the nonlinear characteristics of the core material. In order to model the eddy currents effects in the magnetic core, Bertotti's work for the eddy currents is used and nonlinear resistors dependent on the magnetic core topology are proposed. A systematic procedure is developed for the determination of the incremental self and mutual inductances of the windings. The nonlinear characteristics of the core material are represented either by a magnetization curve or by a hysteresis loop. The hysteresis loop is introduced either by the mathematical model proposed by Tellinen or by the macroscopic model presented by Jiles-Atherton. Simulations results are compared to published measurements in order to verify the proposed model. [ABSTRACT FROM AUTHOR]

Published
2009
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